1. Field of the Invention
The present invention relates to random access memory (RAM) cells and read only memory (ROM) cells, and particularly to mixed mode RAM/ROM cells using antifuses.
2. Description of the Related Art
Random access memory (RAM) cells and read only memory (ROM) cells are well known in the art. A RAM cell stores a logic state, i.e. a logic one or a logic zero, and needs a constant DC voltage to maintain its configuration. Thus, a RAM cell can be reprogrammed by turning the power off, thereby providing design flexibility. A ROM cell also stores a logic state, but is non-volatile, i.e. retains its logic state even in the absence of DC voltage. Thus, ROM cells provide protection against power loss, but fail to provide design flexibility. Therefore, a need arises for a memory cell having the design flexibility of a RAM cell as well as the non-volatility capability of a ROM cell.